1. Field of the Invention
The present invention relates to a preparation of asphalt and its application as a paving material, more specifically, to an asphalt additive and its application.
2. Description of the Related Art
Recent tendency for road focusing on the convenience, high-quality, durability, and environmental friendliness rather than its former emphasis on mere transport function of materials and personnel has been increased, leading to higher demand for replacement of the conventional road.
The conventional asphalt mixture widely used for road pavement is a mixture for hot mixing and hot application of asphalt as specified in KSF 2349. This mixture is produced by a mechanical forced mixing facility (asphalt mixing plant) through mixture of smashed rocks, sand, and mineral powder at 150˜170° C. according to mixing requirement, which is delivered to the construction site by means of various transportation vehicles, such as dump truck. The mixture is paved in situ at above 125° C. by the finisher, roller, or other suitable means, which is then finished according to the specified level of construction requirements depending on vehicle loads.
AP-3 (complying with asphalt specification) is mainly used in Korea as a binding agent, which should meet the following specification in accordance with KSM 2201 (Specification of Asphalt for Pavement).
ItemsConditionsLimitsPenetration degree25° C., 100 g, 5 sec85˜100Ignition temperatureCOC, ° C.NLT 230Ductility(25° C., 5 cm/min) cmNLT 100Penetration degree after%NLT 47heating of thin film(Against the basic penetrationdegree)Ductility after heating of(25° C., 5 cm/min) cmNLT 75thin filmSoluble trichloroethane%NLT 99* NLT: Not less than 
However, one of major problems observed in the conventional asphalt mixture is that paving cannot be conducted when the temperature is below zero. Indeed, the guidelines on road pavement provided by the Ministry of Construction and Transportation require that pavement should not be done below 5° C. Further, in summer, various problems, such as the rutting of road surface, irregular corrugation along the longitudinal section, labelling arising from plastic deformation, bleeding of asphalt fluid due to increase of road load, repetitively occur, leading to decrease of durability owing to the resultant crevices, holes, and ablation. So, re-pavement or repair of road is repetitively required every four to five years, which greatly contributes to increase of budget for maintenance of road, compared to that for new construction of roads.
Moreover, in the conventional road, a sound-absorbing wall has been used to block the noise from traffic. If it does not work for sufficient reduction of noise, another window for prevention of noise is additionally installed. Such installation of the sound-absorbing wall or window is very expensive. When they are not effective in blocking of noise, there has been no choice but control the traffic speed.